This invention relates to a method of fabricating a molded article, and particularly to a method of delivering a settable mixture to a mold tool.
Many methods of fabricating molded articles include the mixing of at least two fluid materials to from a settable mixture that is discharged into a mold tool. The fluid materials typically include at least two reactive components that harden when mixed. Variations in mold tool temperature, settable mixture components and injection speeds can cause variations between molded articles fabricated using the same molding system.
A further challenge to current molding operations is the evacuation of air initially trapped within a mold. Typically an air passage is provided for the evacuation of air from a mold tool as the settable mixture is discharged into the mold tool. Air is expelled from the mold by the introduction of the settable mixture into the mold. For molded articles with simple shapes such an air exhaust passages is adequate. However, for molded shapes having extreme and dramatic shapes and contours air can become trapped within the mold. Further, the completed molded article may include cosmetically important surfaces that preclude the optimum placement of air exhaust passages. The entrapment of air within the mold tool causes voids to be present within the completed molded article, which provides an undesirable appearance and weakens the final molded product.
For these reasons it is desirable to develop a molding system that can accommodate variations in the molding process to provide a consistent, reliable and repeatable molding process.